This invention features improvements in transmission means and more particularly the encapsulation of a transmission to present it in a unitized form the construction of which provides that its housing forms a medium for transmitting its output. While the invention will be illustrated with reference to the embodiment therein of the features of a unique output speed-controlled transmission system forming the subject matter of the claims of the aforementioned co-pending application for United States Letters Patent, it will be seen from the disclosure that the invention features may equally be advantageously employed in conjunction with conventional transmission systems. In any case, the basic invention on which the claims of the present disclosure are based is such to provide a unitary structure which may be easily and effectively applied in connection with a drive system and even embodied as the hub of a driven rotary element having significant economic and environmental benefits, particularly when embodied in conjunction with the aforementioned unique output speed-controlled transmission. Accordingly, such output speed-controlled transmission is fully detailed to provide illustrative examples of embodiment of the present invention. With this in mind, the following information must be considered.
In efforts to produce more efficient transmissions, prior art workers have devised a number of means to control drive train ratio. These controllers, however, are responsive to the input shaft speed. Furthermore all prior control systems related to control of drive train ratios known to applicant require an increase in the speed of the input shaft of the transmission to produce an increase in the speed of its output shaft.
For example, in standard hydraulic automatic transmissions having automotive application, the gear train ratio is controlled primarily by the speed of the automobile engine. That is, on increasing engine speed hydraulic pressure changes effect change in the transmission ratio and the transmission output speed is correspondingly increased. In conventional pulley belt transmissions, centrifugal weights or the like in the transmission input shaft effect a decrease in pulley ratio with an increase in the input shaft speed.
By means of the present invention a new and improved speed-controlled transmission system has been developed wherein the control of the respective speeds of the input and output shafts is determined by means in association with the transmission output shaft and responsive to its speed. This transmission may be so designed as to effect an increase in the speed of rotation of the input shaft in correspondence with and as a result of the speed of rotation of the output shaft. Moreover, it offers two additional distinct capabilities, after initial startup, not inherent in conventional systems. It may be so designed as to have the input shaft turned at a speed which is decreased in respect to the output shaft speed and vice versa. The transmission may also be arranged to maintain a constant speed at the input shaft with an increasing output shaft speed.
A significant consequence of the transmission system of the invention is its inherent capabilities to effectively diminish air pollution in use of an internal combustion engine.
Much attention has been recently given to the problems of emissions control. A primary difficulty in achieving proper emissions control, in automotive vehicles, for example, lies in the fact that for each automotive engine speed there are many variables to be considered, such as air-fuel ratio, spark advance, cam timing and the like. Since optimum conditions of these variables will change for different engine speeds, it is substantially impossible to design an engine which optimizes the variables to produce minimum emissions for the full range of speeds of an operating engine. By contrast, in using the transmission system of the present invention, the engine speed could be caused to remain at a predetermined constant regardless of the vehicle speed (after an initial change of engine speed during start-up) and the variables could be adjusted to give minimum emissions at that predetermined speed. Furthermore, this predetermined engine speed could be so chosen as to cause the engine to operate at its maximum power output speed, regardless of the automobile speed.
Consider also, in a number of vehicles, such as minibikes, snowmobiles and the like, which currently employ pulley belt systems, the engine speed increases with vehicle speed with the result that the vehicle speed is limited by the engine speed and not by the power required to drive the vehicle at high speed. Through the use of the transmission system of the present invention, the maximum speed potential of such vehicles could be realized since at high vehicle speeds the engine could be made to operate at a safe speed, and one at which it produces maximum horsepower.
Pedal powered devices such as bicycles and the like are prime examples of vehicles, the speed of which is limited by the input speed. To overcome this problem prior art workers have devised systems employing up to 15 different gear ratios. These systems are complex and require the slipping of a chain from one gear to another to effect a ratio change. Substitution of the invention transmission would enable a cyclist to pedal at a constant speed (after an initial startup phase) regardless of the vehicle speed and no manual gear changes would be required. This will be described.
The transmission of the present invention may also be advantageously used in electric motor-powered devices. When an electric motor is used to drive a piece of equipment characterized by high inertia, the electric motor tends to accelerate to its operational speed before the equipment during startup. This can result in excessive belt slippage when using a conventional transmission. Through the use of the present transmission, the motor could operate at its maximum power during startup without belt slippage.
A most significant incident of the present invention is the evolution of a unitized speed-controlled transmission the nature and character of which is such to enable a transmission to be easily and effectively installed by one having little experience or knowledge of the transmission art. It is a characteristic of invention embodiments that the housing for the transmission forms a functional part thereof and in fact an element through which the output of the transmission is routed. As mentioned previously, the incorporation of the features of the output speed-controlled transmission described herein provides embodiments of the invention having important consequences in the development of the transmission art.